Research is beginning to unlock the secret role of blood-sucking ticks in sick koalas in an attempt to help conserve the marsupial.
In one of the biggest studies of sick koalas in Australia, Murdoch University researcher Amanda Barbosa has analysed 168 wild koalas that were being treated in koala hospitals for illness or trauma.
Dr Barbosa studied the ticks and blood samples collected from the koalas and, using a new methodology that allows scientists to simultaneously detect DNA sequences of multiple parasite species, made a surprising discovery.
‘‘For the first time, we were able to identify mixed infections with up to five different species of the parasite called Trypanosoma, within the same koala,’’ she said.
‘‘This is important because it gives a clearer picture of the diverse nature of parasites that potentially contribute to disease in our koala populations.’’
Australia Zoo Wildlife Hospital veterinary scientist Amanda Gillett said that although chlamydia and koala retrovirus had been identified as the greatest threat to some koala populations, there was still little understanding of other disease threats in the species.
‘‘This latest research has shown that there are likely to be many yet to be identified infections in koalas, and only with further research will we begin to unravel what role they may also play in the decline of the koala,’’ she said.
In 2006 Dr Gillett first identified Trypanosoma in an ill koala and contacted Murdoch University.
‘‘It is truly fantastic to see how far this research has come and how many different trypanosomes have now been identified since then,’’ she said.
‘‘Hopefully further research will help us elucidate the clinical role these infections may play in our koalas.’’
Port Macquarie’s Koala Hospital clinical director Cheyne Flanagan said the research would strengthen efforts to conserve koalas.
‘‘The role of ticks is to suck blood. They are a vector for transmitting disease or parasites so we shouldn’t be surprised at this discovery,’’ she said.
With her research, Dr Barbosa has charted new base-line data that provides new insights into the cause of disease and will help improve the conservation of a national icon.